Projectile with hollow explosive charge

ABSTRACT

A projectile having a body with an explosive charge having a cavity. A lagging is located in the cavity and a passage in the charge extends centrally rearwardly from the cavity. A primary detonator for the charge is before firing located in a position of rest and after firing is located in an ignition position at the front end of the passage. A secondary detonator is situated in its position of rest in the cavity and a rod extends through the passage having the secondary detonator fastened to the forward end thereof and which on firing is adapted to slide to the rear in the passage.

llnited States Patent [72] Inventors Robert Apotheloz Wallisellen; Hans-Ulrich Bigler, Opfikon; Rene Kessler, Zurich, Switzerland [21] Appl. No. 800,161

[22] Filed Feb. 18, 1969 [45] Patented May 25, 1971 [73] Assignee Werkzeugmaschinenfabrik Oerlikon- Buhrle AG Zurich, Switzerland [32] Priority Mar. 7, 1968 [3 3 Switzerland 41 moment: wnnnzrnrwmrosve Primary Examiner-Samuel Feinberg Assistant Examiner-C. T. Jordan AttorneyWender0th, Lind and Ponack ABSTRACT: A projectile having a body with an explosive charge having a cavity. A lagging is located in the cavity and a passage in the charge extends centrally rearwardly from the cavity. A primary detonator for the charge is before firing located in a position of rest and after firing is located in an ignition position at the front end of the passage. A secondary detonator is situated in its position of rest in the cavity and a rod extends through the passage having the secondary detonator fastened to the forward end thereof and which on firing is adapted to slide to the rear in the passage.

PATENTEUHAY 2 5 I97! SHEET 1 [IF 2 ROBERT APOTHELOZ HANS-ULRICH BIGLER RENE KESSLER INVENTO s ATTORNEYS PROJECTILE WITH HOLLOW EXPLOSIVE CHARGE The invention relates to a projectile having a hollow explosive charge provided with an inserted lagging and also having a detonator which before the firing of the projectile'is situated in a position of rest and after firing is situated in an ignition position at the rear end of a passage extending centrally towards the rear from the tip of the cavity in the explosive charge.

In a known projectile of this type the detonator is situated before firing in a cylindrical chamber extending to the rear from the bottom of the projectile. An arrangement of this kind is disadvantageous for example when the projectile is to be used as a secondary projectile in a carrier projectile. Such secondary projectiles are disposed in rows one behind the other in the carrier projectile. A chamber projecting to the rear beyond the bottom of the projectile therefore needs additional space, so that fewer secondary projectiles can be accommodated in the carrier projectile.

The aim of the invention is to obviate this disadvantage and the projectile according to the invention is distinguished in that the detonator is situated in its position of rest in the cavity of the explosive charge and is fastened on the tip of a rod which extends through the passage and on the firing of the shot is adapted to slide to the rear in said passage.

An example of construction of the projectile according to the invention is described in detail below with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section through a subsidiary projectile with a wall of a carrier projectile,

FIG. 2 is a longitudinal section through the subsidiary projectile illustrated in FIG. 1, during flight after detachment from the carrier projectile,

FIG. 3 is a view from the rear ofthe projectile,

FIG. 4 a longitudinal section through the front portion of the projectile on a larger scale, before the firing of the projectile, and

FIG. 5 is a longitudinal section through the front portion of the projectile on a larger scale, after the firing of the projectile.

According to FIG. 1, the projectile has a body I with a thinwalled cylindrical front portion 2 and also a thick-walled rearwardly conical rear portion 3. This rear portion 3 has on the outside grooves 4 which extend in the peripheral direction and which serve as predetermined fracture points. The rear portion 3 thus constitutes a fragmentation wall. The front portion 2 of the projectile body 1 is provided on its inside with a shoulder 5. In front of this shoulder 5 the front portion 2 has a part 8 the wall of which is thinner than the remainder of the wall of the portion 2. A ring 6 is supported on the shoulder 5 and is fastened on the portion 2 of the projectile body by a flanged-over edge 7 of the part 8. The rear end face 11 of the ring 6 has an edge 9 which serves to center a hollow conical lagging 10. This lagging is preferably made of copper. The rear end face 11, situated at right angles to the axis of the projectile, of the ring 6 forms a stop for the lagging 10. A sleeve 12 is fastened to the rear end of the lagging 10. The sleeve 12, which is preferably made of plastics material, extends to the rear from the lagging 10 and is disposed coaxially to the latter and to the projectile body 1. The projectile body I, lagging l0, and sleeve 12 form an annular space. This annular space contains a hollow charge 13 of explosive material. A projectile bottom 15 is fastened on the rear portion 3 of the projectile body. An annular booster charge 14 is disposed in an annular space at the rear end of the hollow charge. At the front the projectile body 1 has a hemispherical cover 16, which is fastened by an annular extension to the ring 6 previously described. This cover 16 has a central bore 17, the axis of which coincides with the axis of the projectile. A sleeve 18 is mounted slidably in this bore 17. A second sleeve 19 extending into the lagging 10 is fastened on said sleeve 18. The front portion of the sleeve 19 contains a primary detonator 20. On the inner wall of the sleeve 19 there is provided an annular shoulder 21 against which an end face of the primary detonator lies. There is also provided on the inner wall of the sleeve 18 an annular shoulder 22, against which a thin sheet metal disc 23 is pressed by the front end face of the sleeve 19. A firing pin 24 provided with a stem 25 is slidably guided in the sleeve 18. This stem 25 of the firing pin 24 is supported on the sheet metal disc 23. The tip of the firing pin 24 projects through the sheet metal disc 23 into the sleeve 19 and is situated in front of the primary detonator 20. In its interior the sleeve 18 is provided with an annular shoulder 26 against which the stem 25 of the firing pin 24 bears in the position illustrated. This shoulder 26 prevents the firing pin 24 from dropping out of the projectile in the forward direction. The outside of the sleeve 18 has a groove 27 extending in the peripheral direction and having a V-shaped cross section. A bore 28 directed transversely to the axis of the projectile is provided in the cover 16 and receives a slidably mounted safety pin 29. This safety pin 29 has a conical point which projects into the groove 27 in the sleeve 18, while the opposite end of the safety pin is supported against the cylindrical wall 30 of a carrier projectile. A carrier projectile of this type is described in detail in the earlier Swiss application No. 1820/68. On the extension on the cover 16 there is provided on the inner side a groove in which one end of a tension spring 31 is fastened, the other end of which acts on the rear end face of the sleeve 19. The tension spring 31 urges the two sleeves 18 and 19 in the forward direction through the bore 17. This displacement of the two sleeves l8 and 19 is prevented by the safety pin 29 as long as its conical tip projects into the groove 27 in the sleeve 18. l

The bottom 15 of the projectile has a central conical bore 33. A rod 32, preferably made of light metal, extends through the bore in the bottom 15 of the projectile and through the sleeve 12. At the-front end of this rod 32 there is fastened a sleeve 34 containing a secondary detonator 35. The front end face of the secondary detonator 35 is situated opposite the rear end face of the primary detonator 20. The rear end of the sleeve 34 tapers towards the rear. The largest outside diameter of the sleeve 34 corresponds to the inside diameter of the sleeve 19 and the outside diameter at the rear end corresponds to the outside diameter of the rod 32. On the rear end of the rod 32 there is fastened a disc 37 which is situated behind the bottom 15 of the projectile. The rear side of the disc 37 has a recess 38 in the form of a segment of a sphere. The disc 37 is situated in a recess in a plate 39. This plate 39 which is preferably made of plastics material, lies against the bottom 15 of the projectile when in its position of rest and has a forwardly directed edge 40 projecting beyond the rear end of the projectile.

According to FIG. 3 the plate 39 has a star-shaped contour with five points. Of these points two neighboring points lie against the inside of the cylindrical wall 30. As can be seen from FIG. 3, the axis of the safety pin 29 lies in a center plane between these two tips of the plate 29 which bear a against the inside of thecylindrical wall 30. On the plate 39 there is disposed a forwardly projecting pin 42 which engages a bore 43 in the bottom 15 of the projectile and forms a rotational coupling between the bottom and the plate 39. Since the distance from the tips 41 of the plate 39 from the axis of the projectile is shorter than the radius of the wall of the carrier projectile 30, rotation of the projectile about its axis into a position in which the safety pin 29 can no longer be supported against the carrier projectile 30 is not possible.

The head 44 of the firing pin 24, the end face of which forms part of the spherical surface of the cover 16, is supported at the rear against a shoulder on said cover. In FIG. 1, two additional secondary projectiles disposed in line with the projectile described above are partly illustrated in elevation in dot-and dash lines. FIG. 1 also shows that in each case by means of the firing pin head 44 of the projectile lying behind it the plate 39 of a projectile is held bearing against the projectile bottom 15 and thus the rod 32 is held inside the projectile.

The mode of operation is clear from the construction.

After the projectile has been ejected from the carrier projectile 30, the safety pin 29 is no longer supported by the wall of the carrier projectile. The pin 29 is therefore driven outwards from the groove 27 by the force of the spring 31 acting on the sleeves 19, 18 and transmitted through the groove wall 46 to the tip of said pin. The sleeves l8, 19 containing the firing pin 24 and the primary detonator 20 are thus freed and pushed by the spring 31 in the forward direction through the cover bore 17 into the position shown in FIG. 2. In this position the primary detonator 20 is at the distance from the hollow charge which is adjusted to the speed of the projectile and is optimum in respect of the effect to be obtained from the hollow charge.

During flight the front surface of the plate 39 annularly surrounding the bottom 15 of the projectile receives a flow of air. The plate 39 is thereby driven backwards, carrying with it the disc 37 together with the rod 32, which thus moves in the lagging l and in the sleeve 12. The rearmost position illustrated in FIG. 2 is reached when the sleeve 34 lies against the wall of the conical bore 33 in the bottom 15 of the projectile. In this position the plate 39 acts as a surface on which forces serving to stabilize the projectile are produced through the action ofthe current of air.

The dynamic air pressure acting on the firing pin head 44 is not sufficient to perforate the disc 23; on impact with the target however the firing pin 24 is driven back into the primary detonator 20. The explosive charge 13 is thereby primed in known manner through said detonator and with the aid of the secondary detonator 35, which is now situated in the region of the booster charge 14, and of said booster charge 14.

On detonation of the explosive charge 13, the cover 16 together with the spring 31 is blown to pieces and springs ofi, so that the action of the hollow charge jet is not impaired. Through the conical construction of the rear portion 3 of the projectile body the effect is achieved that the fragments into which said body is broken up fly off in a direction which forms with the rearwardly directed axis of the projectile an angle which is smaller than or at most equal to The thickness of the wall ofthe lagging 10 is such that in the event of unintended ignition of the detonators 20 and 35, which are in the position of rest, the detonation will not be transmitted through the lagging 10 to the explosive charge 13. We claim:

1. A projectile comprising a body having a bore, an explosive charge in said body having a cavity, a lagging located in said cavity, a passage in said charge extending centrally rearwardly from said cavity, a sleeve slidable in said bore, a primary detonator fixed in said sleeve for said charge which before expulsion of the projectile .is located in a position of rest and after expulsion of the projectile is located in an ignition position, a secondary detonator situated in its position of rest in said cavity, a rod extending through said passage having said secondary detonator fastened to the forward end thereof and which on expulsion of the projectile is adapted to slide to the rear in said passage.

2. A projectile according to claim 1 wherein a guide device is mounted on said rod which upon expulsion of the projectile is moved by air resistance out of a position of rest into operative position.

3. A projectile according to claim 2, wherein said guide device comprises a stabilizer directed transversely to the axis of the projectile on which dynamic air pressure acts.

4. A projectile according to claim 1 wherein the thickness of said lagging is such that the explosive charge cannot be primed by said secondary detonator. 

1. A projectile comprising a body having a bore, an explosive charge in said body having a cavity, a lagging located in said cavity, a passage in said charge extending centrally rearwardly from said cavity, a sleeve slidable in said bore, a primary detonator fixed in said sleeve for said charge which before expulsion of the projectile is located in a position of rest and after expulsion of the projectile is located in an ignition position, a secondary detonator situated in its position of rest in said cavity, a rod extending through said passage having said secondary detonator fastened to the forward end thereof and which on expulsion of the projectile is adapted to slide to the rear in said passage.
 2. A projectile according to claim 1 wherein a guide device is mounted on said rod which upon expulsion of the projectile is moved by air resistance out of a position of rest into operative position.
 3. A projectile according to claim 2, wherein said guide device comprises a stabilizer directed transversely to the axis of the projectile on which dynamic air pressure acts.
 4. A projectile according to claim 1 wherein the thickness of said lagging is such that the explosive charge cannot be primed by said secondary detonator. 